The operator of the crippled Fukushima Daiichi nuclear power plant says it still cannot obtain accurate data on the water level and pressure of the Number 2 reactor. It says a provisional measuring device installed earlier this week is not operating properly.

Tokyo Electric Power Company believes that readings by the original device are incorrect due to damage suffered in the March disaster.

Workers at the utility company entered the Number 2 reactor building and installed the provisional gauge on Wednesday. The company initially planned to have the gauge begin providing data on Thursday.

But it says as of Saturday, the device is not yet working properly.

TEPCO says this is because the temperature near the reactor containment vessel is so high that water inside the device’s pipes has evaporated.

Fuel meltdowns are believed to have occurred at the Number 1 through Number 3 reactors, leading to a possibility that there is little water left inside the Number 2 reactor.

Accurate measurement of the water level is essential for ensuring stable cooling of the reactor.